Why did the Eastern Roman Empire survive?

In this video, we will ask ourselves the question how the eastern roman empire survived for another millenia. Enjoy the video!

Music: Crusade- Kevin Maclleod

First map of east and west rome: By Geuiwogbil at the English Wikipedia, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=1455678

Second map of western and eastern rome: Von 628px-Western and Eastern Roman Empires 476AD(3).PNG: Bigdaddy1204Europa60AD named es.svg: Rowanwindwhistlerderivative work: Rowanwindwhistler (Diskussion) - 628px-Western and Eastern Roman Empires 476AD(3).PNGEuropa60AD named es.svg, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=48977011

I do not own any of the images shown in the video.